Upstream Particulate Reduction Device for Self-Regenerating Exhaust Systems
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Solution Overview
Problem
Conventional particulate filters in internal combustion engines are large, complex, and expensive due to the need for regeneration hardware and sensitivity to temperature variations, limiting design and placement flexibility, and often require frequent regeneration cycles.
Innovation Solution
A particulate reduction device is positioned upstream of the turbine in the exhaust system, utilizing a flow-through design with self-regenerating filter elements that oxidize particulates based on residence time and temperature, reducing the need for supplemental regeneration hardware and allowing continuous operation under high engine loads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If conventional particulate filters are used with regeneration hardware, then particulate matter is reduced, but device complexity and expense increase
Solution Approach 1:
The particulate filter is designed to be self-regenerating by utilizing the engine's own exhaust heat to combust accumulated particulates. The filter positioned upstream of the turbine captures particulates, and the natural thermal energy from exhaust gases raises the temperature sufficient for oxidation and combustion of trapped particles, eliminating the need for external electrical heaters or fuel injection systems.
Solution Approach 2:
The invention extracts and removes the complex regeneration hardware (electrical heaters, fuel injection devices, specialized controls) from the system entirely. By relying on the natural thermal properties of exhaust gases and the filter's positioning upstream of the turbine, the system achieves regeneration without these extracted components.
2Use of energy by moving object
If filter is positioned upstream of turbine, then regeneration is facilitated by higher exhaust energy, but temperature variations cause problems in filter materials
Solution Approach 1:
The invention changes the material parameters of the filter by using ceramic foam or cordierite materials that are specifically selected for their high temperature stability and resistance to thermal shock. These materials can withstand the wide temperature fluctuations and high exhaust temperatures upstream of the turbine without degrading, unlike conventional filter materials.
Solution Approach 2:
The filter employs composite ceramic structures (foam or cordierite) that combine thermal stability with filtration capabilities. These composite materials provide both the mechanical strength needed to withstand temperature variations and the porous structure required for particulate capture and regeneration.
3Loss of time
If filter volume is increased to accumulate more particulate matter, then regeneration frequency is reduced, but system size and cost increase
Solution Approach 1:
The filter enables continuous or near-continuous regeneration by maintaining optimal operating conditions upstream of the turbine. The consistent high exhaust energy and temperature allow particulates to be combusted regularly, preventing large accumulations and eliminating the need for oversized filters or infrequent regeneration cycles.
Solution Approach 2:
The system utilizes periodic regeneration cycles triggered by natural exhaust temperature peaks during engine operation. Rather than requiring large storage capacity, the filter is designed to regenerate periodically when exhaust conditions are favorable, maintaining a balance between particulate accumulation and combustion opportunities.
4Reliability
If precious metal catalysts are used for continuous regeneration, then regeneration effectiveness is improved, but expense increases
Solution Approach 1:
The invention replaces expensive precious metal catalysts with lower-cost ceramic materials (alumina, cordierite, or foam structures) that achieve regeneration through thermal combustion alone. While these materials may have shorter lifetimes under extreme conditions, they provide cost-effective continuous regeneration capability without requiring platinum, palladium, or rhodium catalysts.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration results in a smaller, more cost-effective system with reduced pressure drop and increased flexibility, enabling continuous regeneration and improved turbocharger performance by harnessing energy from combusted particulates, while maintaining effective particulate reduction without the need for expensive catalysts.
Implementation Method 1
combustion of particulates to an extent sufficient to meet a residence requirement
Implementation Method 2
heating the particulate matter to a temperature at which the trapped particles combust or oxidize
Data Source
AI summary
An internal combustion engine system includes an engine having an engine housing. The engine system further includes an exhaust system, and a turbine disposed within the exhaust system. A particulate reduction device is disposed in the exhaust system upstream of the turbine. The particulate reduction device includes an exhaust retarder having a flow property which is based at least in part on a residence requirement for combustion of particulates in exhaust gases passing therethrough. The flow property may be a flow restriction property, and the exhaust retarder may include a flow restricting trapping element configured to trap particulates in the exhaust gases. The flow restricting trapping element defines a combustion efficacy to exhaust mass flow and temperature coefficient for the particulate reduction device which is based at least in part on a combustion initiating residence requirement for particulates passing through the particulate reduction device.